Fluid shock absorbing/momentum dampen-ER and shock absorbing/momentum dampening system for packaging delicate objects and equipment

ABSTRACT

A fluid shock-absorbing/momentum dampening system for packaging delicate objects or equipment (electronic, disk drive, computer, computer screen, optics, lenses binocular, telescope, or other delicate objects or equipment). A system that accelerates a fluid when a member is compressed and/or by using a fluid to reduce an object&#39;s kinetic energy, or by using an object&#39;s buoyancy to reduce an objects relative momentum. Built by a variety of means a fluid shock absorber/momentum dampen-ER offers superior shock absorption characteristics over conventional approaches.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] Application No. 60/469,331 Filing Date May 9, 2003 Confirmation #8163, is a Provisional Patent for which this application is anon-provisional Utility Patent follow up by the same inventor Robert J.Rapp.

FEDERAL RESEARCH STATEMENT

[0002] [Not Applicable: this invention was developed on my own time andwith not government assistance.]

BACKGROUND OF INVENTION

[0003] The absorption of shock is becoming a more important aspect inprotecting electronic devices, optics, and other fragile/delicateobjects or devices from damage.

[0004] Computers made to resist the shock from dropping use expensivecases made from magnesium or other costly metal and shock mount fragiledevices (like disk drives) with an elastic or spring suspension. Thisapproach typically provides a moderate level of energy absorption thatis proportional to k x (where k is a spring constant and x is thedimension the spring is compressed or elastic is stretched).

[0005] Other Approaches Include:

[0006] Packaging fragile devices inside of an external impact case wherethe device is suspended by foam. Here, typically k is low and x islarge, providing moderate to high levels of impact resistance at thecost of an increased package size.

[0007] Mounting the device inside of a soft case. Here typically both kand x are low, providing limited shock absorption.

[0008] Designing a case that is fragile, where the case fractures beforedamaging the internal device.

[0009] Each of these approaches has limitations. One of these is relatedto the k x function's effectiveness versus device size, another relatesto undesirable and limited usefulness of a breakable case.

[0010] For the k x function to yield high shock resistance either k or xor both have to be large.

[0011] If k is large there will be little or no shock absorption formedium impacts, impact levels that may still damage delicate devices. Ifk is small the shock absorber is only useful for low or perhaps mediumimpacts. If x is large the overall device's size must be larger. If x issmall k x will also tend to be smaller. Given this, typical spring orelastic shock absorption approaches have significant limitations, whichprovide a narrow or limited useful range or an increase in size.

[0012] Damaging the case to protect the device only provides limitedprotection. If the device receives multiple repeated shocks, theapproach may be useless. For example, if the device tumbles down a setof stairs with pieces breaking off on each impact, until finally thedevice itself is broken. Yet again even if the device is protected,living with a broken case is undesirable.

[0013] Distinctions may also be made between shock absorption andmomentum dampening. Shock absorption includes the instantaneousdissipation of impact force and the dampening over time of impactenergy. Momentum dampening may be described as cradling against theeffects of sudden deceleration or the reduction of momentum/kineticenergy of the delicate object. Each of these effects are closely relatedthrough and due to implementation methodology.

[0014] A shock absorber/momentum dampen-ER with an energy absorptionfunction that scales with impact energy would transcend the limitationsof typical energy absorption methodologies and would provide a solutionthat has a large dynamic or useful range. A fluid shockabsorber/momentum dampen-ER accomplishes this very goal by acceleratingfluid, the harder the shock force the faster fluid is displaced, themore energy & momentum are absorbed. A fluid shock absorber provides amethod for absorbing shock that scales in a non-linear way as comparedto an object's impact velocity.

[0015] A fluid shock absorbing/momentum dampening system made toaccelerate a fluid through constrictions or by immersing an object in afluid provides a packaging solution that is effective and costefficient. Furthermore fluid shock absorbers may be built such that theyprovide soft and compliant surfaces designed to protect and cradledelicate objects of various sorts.

SUMMARY OF INVENTION

[0016] Considering the following fundamental principals, a new form ashock absorber, a fluid shock absorber/momentum damper-ER may be made invarious configurations:

[0017] Fluid power has been used for many years to make lifts, jacks,and hydraulic actuators. In fact a small person can pump a hydraulicjack by hand and lift a car.

[0018] Specialty fluids have been developed to cool entire computersystems.

[0019] Elementary physics describes the energy (e) required to force afluid through a nozzle as: e=½Δm v²(½ of the mass of the fluid movingthrough the nozzle times the square of the change in the fluidsvelocity).

[0020] Fluid energy derived from shock absorption may be directed toreduce the kinetic energy of an internally packaged object.

[0021] Fluid displaced though shock absorption action may be used tocradle an object.

[0022] An object moving in a fluid or with relative motion to a fluidwill experience a drag force that will tend to abate any relativekinetic energy or momentum that the object has.

[0023] A buoyant object immersed in a fluid will float. If the object ispackaged inside of a case and dropped the objects buoyancy will tend toreduce relative momentum between the case and the object.

[0024] Since applying pressure to a fluid such that the fluid is passedthrough a small restriction like a hole, a group of holes, or a nozzle,uses energy in a non-linear way, a fluid shock absorber would absorbenergy in that same way e=½Δm v². Additionally since fluid can be usedto dampen an internally packaged object's kinetic energy, cradle adelicate object, or an objects buoyancy may be used to reduce an objectsrelative momentum, more than one mechanism may be used to protectdelicate objects from shock energy. Thus a fluid shock absorber/momentumdampen-ER may use one or several mechanisms to protect delicate objectsby using a soft yet dynamic shock absorber.

[0025] Delicate objects include, yet are not limited to electronics,computer boards/chips, disk drives, computer screens, optics lenses,binocular, telescope, plates, or other delicate/fragile items.

BRIEF DESCRIPTION OF DRAWINGS

[0026]FIG. 1: A Fluid Shock-Absorbing, Momentum Dampening System shows aDelicate Object (1) in a Liquid Bath (2) supported by various fluidshock absorber mechanisms (4-9) and contained within a case (3), aportion of the case is depicted.

[0027] Here shock absorbers Include, a bellows (4), other compressiblemember/membrane (5), piston-cylinder mechanisms (6-9).

[0028] When the assembly is dropped the case hits the ground first: dropforce impacts the case (10, large arrows). At this point the delicateobject still has momentum relative to the case, as the delicate objectmoves downward compressible members are compressed and eject fluidthrough a series of holes in the compressible members. Ejected fluid aredepicted by sets of small arrows, here the ejected fluid is directedupward toward the delicate object. The accelerated fluid provides shockabsorption, and fluid directed against the object's momentum providesmomentum dampening.

[0029] Note: There are two piston-cylinder arrangements shown oneconsisting of cylinder (6) and piston assembly (7, 7 a, & 7 b), and thesecond consisting of cylinder (8) and piston (9). Piston (7) consists ofa two stage piston (7 a & 7 b), here fluid is accelerated from cylinder(6) through part of the piston (7 b) providing momentum dampening to (7a): Fluid is then accelerated through (7 a) and provides momentumdampening directly to the delicate object (1).

[0030]FIG. 2: Source and Sink Vessels, here various mechanisms forconstructing fluid shock absorbers are shown (Compress-Expand Vessels,Bulb-Balloon, Bellows-Balloon, Relative Motion between a fragile objectand a fluid, Bellow-Changeable internal Volume Vessel 1, andBellows-Changeable internal Volume Vessel 2).

[0031] Source vessels contain a fluid and eject that fluid into a Sinkvessel when a force is applied to them. Source vessels have holesleading to Sink vessels, and Sink vessels are designed to return totheir original configuration through the use of spring loading orelastic force.

[0032] In the case of an object immersed in a fluid on springs orelastics the Source and Sink vessels may be the same: as in the RelativeMotion between a fragile object and a Fluid implementation.

[0033] Compress-Expand Vessels: In this drawing a force acts uponcompressible vessel (11), as this occurs fluid is forced out ofcompressible vessel (11) and into expandable vessel (12). Constrictingelastics (13) stretch as the expandable vessel fills with fluid. Whenthe force is removed constricting elastics (13) force the fluid backinto compressible vessel (11) Bulb-Balloon: In this drawing a force actsupon a rubber bulb (16), as this occurs fluid is forced out of rubberbulb (16) and into a tight balloon (17). The balloon stretches as itfills with fluid. When the force is removed spring force in the balloonforces the fluid back into the bulb (16).

[0034] Bellows-Balloon: In this drawing a force acts upon a bellows(14), as this occurs fluid is forced out of the bellows (14) and into atight balloon (15). The balloon stretches as it fills with fluid. Whenthe force is removed spring force in the balloon forces the fluid backinto the bellows (14).

[0035] Relative Motion between a fragile object and a Fluid: Here adelicate object (20) is immersed in a fluid and suspended by non-rigidsuspensions (springs or elastics). The drawing depicts relative motionbetween the fluid (f) the delicate object (20) where momentum of theobject is shown as (M). NOTE: To provide more clarity the external caseand suspensions are not depicted. The large up-arrow marked (B) refersto buoyancy of the delicate object (20). Fluid (f) washing over surfacesof and through holes in the delicate object (20) absorb shock and reducethe object's momentum (M). Buoyancy (B) provides flotation that resistsfalling momentum when the device is dropped.

[0036] Bellows-Changeable internal Volume Vessel 1: In this drawing aforce acts upon a bellows (21), as this occurs fluid is forced out ofthe bellows (21) and into a solid vessel (22) that has a changeableinternal volume. Here a compressible foam (23) compresses as fluid flowsinto the solid vessel (22).

[0037] Bellows-Changeable internal Volume Vessel 2 In this drawing aforce acts upon a bellows (24), as this occurs fluid is forced out ofthe bellows (24) and into a solid vessel (25) that has a changeableinternal volume. Here as fluid flows into solid vessel (25) and pushesagainst a compressible piston (26, 27). This compressible pistonconsists of a spring (27) and a gasket (26).

[0038]FIG. 3: Compressible V.S. Rigid Case Fluid Dynamics: This drawingshows a delicate object packaged within a compressible semi-rigid caseand a rigid case each using fluid shock absorption/momentum dampening.Note the drawings are marked CCA, CCB, CCC, RCA, RCB, and RCC: CC meansCompressible Case and RC means Rigid Case.

[0039] The cases depicted In normal configuration are labeled CCA, &RCA: Drop Impact Force configuration are labeled CCB, RCB, andCompression Force configuration are labeled CCC, RCC.

[0040] Drawings CCA, CCB, and CCC show the compressible semi-rigid case,a delicate electronic mechanism (30) is supported by compressible fluidsource vessels (31L & 31R), and expandable sink vessels (32U & 32D).Upper and lower rigid surfaces are also shown (33U & 33D).

[0041] Drawings RCA, RCB, and RCC shows a fluid filled rigid case (37)where a delicate electronic mechanism (35), is supported by a field ofcompressible fluid shock absorbers (36R, 36L, 36U, & 36D).

[0042] Drop Impact Force shown in CCB and RCB depict relative motion ofthe case in respect to the electronic device packaged within when thecase is dropped.

[0043] Notice in CCB that source vessels (31L, 31R) compress expandingsink vessels (32U, 32D): Compression of the source vessels expels fluidinto sink vessels absorbing shock and reducing the momentum of theelectronic device (30). The expanding vessels (32U, 32D) cradle thedevice (30).

[0044] Notice in RCA that downward fluid shock absorbing bellows (36D)are compressed and upward fluid shock absorbing bellows (36U) arestretched, acceleration and movement of fluid in and out of the bellowsabsorb shock and reduce momentum of the electronic device (35).

[0045] In CCC the Compressible Case compresses (33U, & 33D) when exposedto a compression force. The device may be placed into a pocket where iswould expand holding itself in place.

[0046] In RCA the rigid case (37) does not compress when exposed to acompression force.

[0047]FIG. 4: Shows a simple One Way Valve for use in fluid shockabsorber. This valve consists of a Flap with Holes (40) and a Holeleading to the Sink Vessel from the Source Vessel (41).

[0048] The one way valve is depicted in the closed position (40A, 41A,40B, & 41B). Fluid flowing from the Source Vessel to the Sink Vessel isdepicted (42), the fluid flowing in this direction forces the Flap withHoles (40A, & 40B) to cover the Hole leading to the Sink Vessel reducingfluid flow area. The covered Hole leading to Sink Vessel is depicted asa circle with a dashed line.

[0049] Flow area difference may been seen by looking the sizes of theholes in the flap (40C) and the size of the hole leading to the sinkvessel (41C).

[0050] Shock Recharging: when the shock recharges fluid flows from theSink Vessel to the Source Vessel through the Hole leading to Sink Vessel(41D), the Flap with holes (40D) is attached to the interior of theSource Vessel at the narrow ends of the flap (43). Notice how the Fluidforces the flap to move away from the hole (41D) increasing the flowarea.

DETAILED DESCRIPTION

[0051] Elementary physics describes the energy (e) required to force afluid through a nozzle (or constriction) as: e=½Δm v² (½ of the mass ofthe fluid moving through the nozzle times the square of the change inthe fluid's velocity). A shock absorber designed to force a fluidthrough a nozzle (or constriction) would therefore dissipate energyfollowing this same equation. This means that the harder a fluid shockabsorber is hit, the more energy it dissipates following the equatione=½Δm v². The shock absorption scales with impact energy because asshock-force increases, more fluid is accelerated to a higher velocity.The performance of a fluid shock absorber is unique, and leads us toseveral possible fluid shock absorber designs.

[0052] Furthermore fluids may be used in other creative ways: directedto reduce kinetic energy, used to cradle/support an object, or simply towash over surfaces to reduce the momentum of an internally packagedobject.

[0053] Shock Absorption and Momentum Dampening: Shock Absorption may bedescribed as a combination of the instantaneous dissipation of impactforce and the dampening over time of impact energy. Momentum Dampeningmay be described as a combination of the cradling against the effects ofsudden deceleration, and mechanisms through which an object's kineticenergy is reduced. These effects are closely related and interactthrough complex functions.

[0054] A fluid shock absorption momentum damper-ER uses a fluid toabsorb shock and reduce the momentum of an object through severalmethods, including:

[0055] Accelerating a fluid through a constriction.

[0056] Immersing a delicate object in a fluid and mounting the object onnon-rigid supports. Where fluid washes over surfaces on the delicateobject acts to absorb a devices kinetic energy.

[0057] Using buoyancy to resist drop shock or to reduce momentum of anobject immersed in a fluid.

[0058] These principals can best be described through a few examples:

EXAMPLE 1

[0059] A fragile device is floated or immersed in a fluid and supportedby an array of small compressible members or bellows (see FIG. 1), anexternal hard case provides a mounting surface for the bellows.

[0060] When the device is dropped the external case impacts the ground,the bellows are compressed as the delicate device is still moving. Thebellows eject fluid from their interior through a series of holesproviding shock absorption. The fluid stream is directed toward thedevice (or against the relative motion of the case's exterior and thedevices falling motion), the fluid's velocity supports the fragiledevice providing momentum dampening.

[0061] Furthermore buoyancy of the device may be used to resist devicemomentum resulting from drop shock. If the device is dropped buoyancywill float the delicate object away from the drop direction andtherefore act to dampen the momentum of the delicate object.

EXAMPLE 2

[0062] A fragile device is supported by a series of fluid filled rubberbulbs, each connected to a tight balloon. An external case provides amounting surface for the bulbs.

[0063] When the device is dropped the external case impacts the ground,the bulbs are compressed as the fragile device is still moving. Thebulbs eject fluid through a small nozzle, filling and expanding theballoons with fluid, thus providing shock absorption. As the balloonsfill with fluid they support/cradle the fragile device providingmomentum dampening. Here the balloons stretch out horizontally as thefragile device's momentum is slowed. In this type of design fluid from afluid Source (the bulb) flows to a fluid Sink (the balloon) when a forceis applied to the fluid Source. When the force is removed fluid flowsfrom the fluid Sink (the balloon) back into the Source (the bulb).

EXAMPLE 3

[0064] A fragile electronic assembly such as a multi-chip module orcircuit board immersed in a fluid and suspended by a springy suspensionand mounted in an enclosure. Holes in the assembly, veins on theassembly, and component surfaces provide shock absorption and momentumdampening. When the device is dropped external case impacts the ground,the electronic assembly continues its falling motion forcing fluidthrough holes and across surfaces. The action of moving fluid absorbsshock and dampens momentum protecting the delicate assembly. Flotationor buoyancy of the electronic assembly will also facilitate momentumdampening of an object that is dropped.

[0065] Examples 1 & 2 demonstrate shock absorption and momentumdampening; where the shock absorption absorbs energy to the equatione=½Δm v².

[0066] In Example 1 if the fluid stream were directed such that thefluid energy slowed the momentum of the fragile device with highefficiency, then nearly 100% of the fluid energy would be acting uponreducing the kinetic energy of the fragile device. Like a fire hosedriven by shock energy. The overall energy absorption of this systemwould approach e_(TA)=(2(½Δm v²))=Δm v², where e_(TA) means TotalAbsorbed Energy.

[0067] In Example 2 the horizontal stretching of the balloons providemomentum dampening that follows a k x (spring like) function. Theoverall energy absorption of this system would approach e_(TA=)½m v²+kx.

[0068] In Example 3 energy dissipation functions are complex anddependant upon many factors Including surface area/geometry, suspensionspring force, buoyancy, and mass. Notably, however the electronicassembly acts as a spring loaded sail.

[0069] Fluid being accelerated being one significant implementation of afluid shock absorption momentum dampening system where the fluid has tomove from one place to another, from one vessel to another or from theInside of a vessel to the outside. A bellows performs this function,simply squeeze the bellows and material inside of the bellows isaccelerated out of the bellows (in this case the material is a fluid).In terms of source and sink, the place where fluid comes from is a fluidsource and where the fluid goes is a fluid sink.

[0070] The fluid shock must also be recharged, or go back into theoriginal configuration. For example the bellows may be spring-loaded: assoon as the shock force has been dissipated, spring loading wouldrestore the shock to the original configuration. Combine this withvalves that enable greater inflow area than outflow area, the shockabsorber could be recharged at a faster rate.

[0071] Making the Invention: There are several ways to build a fluidshock absorber and fluid shock absorbing members, these include, but arenot limited to:

[0072] A bellows, when compressed forces a fluid through a nozzle andinto an expandable vessel.

[0073] A rubber bulb, and a balloon. The rubber bulb when compressedforces fluid into a tight rubber balloon (an expandable vessel). Whenthe compression force ends, fluid is forced back into the bulb from thespring force of the balloon.

[0074] A piston and cylinder when compressed forces fluid through aconstriction.

[0075] A fragile device immersed in a fluid on a springy suspension andmounted in an enclosure. Would act as a shock absorption/momentumdampening system. The surface area of the device moving in the fluid andthrough holes in the device would provide shock absorption/momentumdampening.

[0076] There are several ways to package delicate devices within a fluidshock absorption momentum dampening system, these include, but are notlimited to:

[0077] A delicate device may be packaged inside of a hard case, immersedin a fluid, mounted on a field of small spring loaded bellows (bulbs, orpiston-cylinder arrangements). When dropped, the bellows are compressedtransferring fluid from inside the bellows to outside, while overallvolume for the fluid remains constant.

[0078] A delicate device may be packaged inside of a case (hard,semi-ridged, or other case) yet supported by a field of rubber bulbs(bellows, or piston-cylinder arrangements). Here when compressed, fluidflows from one series of vessels to another (from fluid Sources to fluidSinks).

[0079] When using a semi-ridged case, squeezing the case could reducethe device's thickness as fluid was transferred from one place toanother. The device could then be placed into a pocket where it wouldexpand, holding itself in place.

[0080] There are also several way to recharge the shock faster:

[0081] Recharge the shock faster by spring loading of the compressiblemember and/or the expandable vessel.

[0082] Recharge the shock faster by using one way valves that provide agreater surface area for pulling in fluid than for ejecting fluid.

FIELD OF THE INVENTION

[0083] Shock absorption is an important aspect for making delicatedevices more robust. Many electronic products and optics are verysensitive to shock. Simply dropping a device may render it unusable.

[0084] Other methods for making a device more shock resistant includeshock mounting the device on springs or springy material, making a softcase, filling a hard case with soft padding, or by designing the to casebreak before the internal device.

[0085] This new approach uses a fluid to absorb shock, a method thatprovides a superior energy absorption capabilities as compared toconventional approaches.

1: Immersing a delicate object in a fluid and mounting the delicateobject on non-rigid members for the purpose of using the fluid forabsorbing shock and protecting the delicate object. This is anindependent claim. 2: Members as in claim 1 where a fluid is acceleratedthrough constrictions and ejected from the member's interior for thepurpose of shock absorption. 3: Members as in claim 1 where the membersare made of springs. 4: Members as in claim 1 where members are made ofan elastic material. 5: Members as in claim 2 where the fluid isdirected in a way that reduces the momentum of the delicate object. 6: Ashock absorber for protecting delicate objects made from a fluid filledcompressible vessel (a source vessel) and an expandable vessel (a sinkvessel), fluid flows from source vessel to sink vessel when force isapplied to the compressible source vessel. This is an independent claim.7: A shock absorber for protecting delicate objects made from a fluidfilled compressible vessel (a source vessel) and a (sink) vessel wherethe internal volume of the sink vessel increases when a fluid is forcedinto it from the source vessel. Fluid flows from source vessel to sinkvessel when force is applied to the compressible source vessel. This isan independent claim. 8: The acceleration of a fluid through one or moreconstrictions between source and sink vessels as in claim
 6. 9: Theacceleration of a fluid through one or more constrictions between sourceand sink vessels as in claim
 7. 10: A shock absorber as in claim 6 wherethe sink vessel is used to support/cradle the delicate object, thusreducing the momentum of the delicate object. 11: A packaging system asin claim 1 where the delicate object is an electronic device. 12: Apackaging system made with shock absorbers as in claim 6 used to packagea delicate object. 13: A packaging system made with shock absorbers asin claim 7 used to package a delicate object. 14: A packaging systemmade from shock absorbers as in claim 6 where the delicate object is anelectronic device. 15: A packaging system made from shock absorbers asin claim 7 where the delicate object is an electronic device. 16: Theuse of one way valves in non-rigid members as in claim 2 that providesgreater surface area for fluid inflow than fluid outflow enabling themember to recharge faster. 17: The use of one way valves in sourcevessels as in claim 6 that provides greater surface area for fluidinflow than fluid outflow enabling the source vessel to recharge faster.18: The use of one way valves in source vessels as in claim 7 thatprovides greater surface area for fluid inflow than fluid outflowenabling the source vessel to recharge faster. 19: The use of Buoyancyto resist drop shock and to dampen momentum/kinetic energy of a delicateobject packaged as in claim 1.